Change-speed gear for bicycles



2%, 3% a J. F. GORDON 1,773,996

CHANGE SPEED GEAR FOR BICYCLES Filed Oct. '7, 1927 Patented Aug. 26,1930 UNITED STATES PATENT OFFICE] JOHN F. GORDON, OF NITRATEPLANT,"-ALABAMA i CHAN GE-SPEED GEAR BICYGLES Application filed October7, earf sriai not 224,553. i

acter designated wherein a simple, effective means is provided fordirect transmission between the driving and driven elements of the gearat high speed and a shift from such'a direct drive to a speed reductionis accomplished by a single shiftable gearm'ember.

In a change speed gear for bicycles and motorcycles, as heretoforeproposed, the parts have been needlessly multiplied, entailing acomplicated, expensive structure and considerable friction in operation.In my improved gear I have reduced the parts to a minimum and produced agear, simple of design, and easy of manufacture and which operates witha'minimum of friction.

Briefly, my invention comprises a driving gear fixedly secured to thepedal crank shaft of a bicycle, a reduction gear train, and a drivengear member, loose on the pedal shaft and having external and internalteeth together with means to connect the driven gear member directlywith the driving gear, or with the reduction gear train.-

Apparatus embodying features of my invention is illustrated in theaccompanying drawing, forming a part of this application, wherein Fig. 1is a sectional view of the gear show- 0 it in low speedposition; Fig. 2is a view similar to Fig. 1, showing the gear in high speed position;and

Fig. 3 is an end view in elevation of Figs. 1 and 2.

Referring now to the drawing for a better understanding of my invention,I show a gear case 10, which may be mounted, in any suitable manner, onthe frame of a bicycle or motorcycle, not shown. Extending through thegear case 10 is a pedal crank shaft 11 having secured thereto pedal arms12 and13. Fixedly secured to the crank shaft 11 is a driving pinion14,andloosely mountedon the crank shaft 11 is the usual sprocket'wheel 16.The sprocket 16 is pro vided with a hub 17 havlng a driyen" gear member18 shiftably mounted thereon, as by toothed or spline connections 19.The drivQ ing gear member 14 is provided withia hub portion '21, similarto .the hub p0rtion17 ofv thesprocket 16. Thehub portion 21 has splinesor teeth 22, similar to 19 of the hub 17 sothat thedriven gear 18 ,mayIbeshifted to cause its internal; teeth orsplines to coact botl'rwiththe hub and thefhub 2 1and thus directly connectth'e driving gear member14 and the driven gear 18, and hence the sprocket 16, for director highspeed drive. The driven I gearmember 18 isshiftable onthe hub 17 bymeans of ashifting arm 23 which may be. actuated fromany suitablesource, asjby the: manually operable shaft 25.

Mounted within the casing 10 isQa countere shaft 26 having mountedthereon a gear member 24 having a toothed portion 27 of a rela tively,large diameterand a toothed portion 28 of a relatively small diameter.The driv-.

ing gear member 14 is, at all times, in mesh with the toothed portion27. The driven'gear member 18 is adapted to mesh with the toothedportion 28 when shifted out of en- I gagement with the driving member14, as

shown in Fig. 1.. In this position of. the I gears, the drive is fromthe crank shaft 11 through the driving gear member 14 to the toothedportion 27 of the gear 24 and the toothed portion 28 of the gear member24,

to the driven gear 18, thereby effecting a reduction in speed or the lowspeed drive. With the gears in the position shown in Fig. 2, the drivengear member 18 is out of mesh with the toothed portion 28 and is inengagement with the driving gear14 through the splines 19 and22,.thereby effecting direct drive from the pedal crank shaft 11 to thesprocket wheel 16, having the countershaft gears 27 and 28 slowlyidling. i

From the foregoing it will be apparent that I have devised an improvedchange speed gear for bicycles, motorcycles and the like, which issimple of construction and op. eration and which operates with a minimumof friction.

While I have shown my invention in but oneform, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various changes and modifications, without departing from the spiritthereof, and I desire, therefore, that only such limitations shall beplaced thereupon as are imposed by the prior art or as are specificallyset forth in the appended claims.

What I claim is: 1. In a change speed gear of the character described, agear b ox,"a driving shaft extending through the gear box and havingdriving members at both ends thereof, a driven Wheel having a hubloosely mounted on the driving shaft and projecting into the gear box, areduction gear train including 'a fioating'gear member splined to thehub of the driven Wheel, a pinion keyedto the driving shaft and having ahub similar to the hubfof the driven Wheel, and means to shift thefloating gear member to telescope over the hub of the pinion and the hubof the driven Wheel or to connect the driven wheel With the gear, train.

. a sprocket loosely mounted on the shaft and.

2. In a bicycle'change speed gear of the character described, a gear'box,a,contin'uous pedal shaftexten'ding through the gear box,

having an elongated hub portion projecting into the gear box andprovided With external 1 teeth, a pinion fixed to the driving shaft andhaving a toothed hub portion similar to the hub portion of the-sprocket,and a gear shiftably mounted on the sprocket hub portion and, adapted totelescope over and engage With the hub portion of the pinion for highspeed. p r

In testimonyrwhereof I, J OHN F. GORDON,

aflix my signature. a JOHN F. GORDON.

